1. Field of the Invention
This invention is directed to a sensor that detects the presence of an electrically conductive fluid such as water and the like in a reservoir. The reservoir may normally contain a non-conductive fluid such as oil or fuel. The presence of water in the reservoir such as a crank case of an engine, an oil pan, a pump crankcase or in any device having splash or oil fed lubrication would normally indicate a problem with some component of the apparatus associated with the reservoir. Thus the sensor can provide a visual or audible indication that there is a problem with the operation of the apparatus.
2. Description of Related Art
U.S. Pat. No. 2,420,177 discloses a sensor including two contacts that are positioned at the lower portion of an oil pan. The sensor is part of an oil plug P. According to the disclosure, metallic particles that are created as a result of the failure of a part of the engine or machine will accumulate in the plug and eventually will bridge the gap between contacts 16 to cause the flow of electricity which will activate signals. U.S. Pat. No. 4,410,885 discloses a sensor 10 mounted in the oil pan of an internal combustion engine that includes an inner electrode 42 and an outer electrode 44 which is formed with a flexible helical coil. The probe is connected to an external battery 26 and warning light 22.
Both devices include several parts which may fail or become contaminated in such a way that would render them inoperative. Both also rely upon an external source of power.